Altering capacitance of MIM capacitor having reactive layer therein

• US 8,363,379 B2
• Filed: 08/18/2010
• Issued: 01/29/2013
• Est. Priority Date: 08/18/2010
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Edelstein, Daniel C., Stamper, Anthony K.
• Primary Examiner(s): Ha, Nguyen T
• Application Number:
  US12/858,953
• Publication Number:
  US 20120044611A1
• Time in Patent Office: 895 Days
• Field of Search: 361/303, 361/305, 361311-313, 361/321.4, 361/272, 361/273, 361277-278, 361/279, 361/283.1, 361/283.3, 361/287, 361290-292, 438295-296
• US Class Current: 361/278
• CPC Class Codes: H01G 7/026 with ceramic dielectric
• CPC Class Codes: H01G 7/04 having a dielectric selected for the variation of its permittivity with applied temperature
• CPC Class Codes: H01G 7/06 having a dielectric selected for the variation of its permittivity with applied voltage, i.e. ferroelectric capacitors electrets H01G7/02
• CPC Class Codes: H01L 28/40 Capacitors
• CPC Class Codes: H01L 28/75 comprising two or more layers, e.g. comprising a barrier layer and a metal layer

Abstract

Embodiments of a method include forming a metal-insulator-metal (MIM) capacitor including a first electrode and a second electrode and an insulator layer between the first and second electrodes, the MIM capacitor also including a reactive layer; and altering the reactive layer to change a capacitive value of the MIM capacitor.

Claims

1. A method comprising:

forming a metal-insulator-metal (MIM) capacitor including a first electrode and a second electrode and an insulator layer between the first and second electrodes, the MIM capacitor also including a reactive layer,

wherein the reactive layer includes a tunable dielectric constant material; and

altering the reactive layer to change a capacitive value of the MIM capacitor, wherein the altering includes creating a dipole moment change in the reactive layer to change a dielectric constant of the tunable dielectric constant material.

2. The method of claim 1, wherein the creating includes exposing the reactive layer to an increased temperature and one of an electronic field and a magnetic field.

3. The method of claim 1, wherein the forming includes positioning the tunable dielectric constant material between at least one of:

the insulator layer and the first electrode, and the insulator layer and the second electrode.

4. The method of claim 1, wherein the dipole moment change creating includes applying a stress by one of pyro-electric and ferro-electric polarization transitioning above or below a Curie temperature of the tunable dielectric constant material.

5. The method of claim 1, wherein the tunable dielectric constant material is selected from the group consisting of:

barium-tantalum-oxide (BaTiO₃), lead-titanium-oxide (PbTiO₃), and potassium-niobium-oxide (KNbO₃).

6. The method of claim 1, wherein the MIM capacitor forming includes creating the insulator layer having a thickness and dielectric constant prior to altering such that an initial capacitive value is within plus or minus three standard deviations of an intended capacitive value.

7. The method of claim 1, wherein the altering occurs after measuring the capacitive value of the MIM capacitor.

8. A method comprising:

forming a metal-insulator-metal (MIM) capacitor including a first electrode and a second electrode and an insulator layer between the first and second electrodes, the MIM capacitor also including a reactive layer,

wherein the reactive layer includes a reactive conductor; and

altering the reactive layer to change a capacitive value of the MIM capacitor, wherein the altering includes stressing to cause at least one of reacting or diffusing of the reactive conductor with the insulator layer to change one of the dielectric constant or spacing between the first and second electrode.

9. The method of claim 8, wherein the stressing includes thermally oxidizing to cause an interfacial reaction between one of the first or second electrodes and the insulator layer that changes the spacing between the first and second electrodes.

10. The method of claim 8, wherein the stressing includes thermal and electrical stressing to cause an interfacial reaction between one of the first or second electrodes and the insulator layer that changes the spacing between the first and second electrodes.

11. The method of claim 8, wherein the reactive conductor is selected from the group comprising:

aluminum (Al), titanium (Ti) and tantalum (Ta), and wherein the reactive layer includes silicon dioxide (SiO2) in contact with the reactive conductor.

12. The method of claim 8, wherein the altering includes heating and applying a voltage of a given polarity and magnitude to cause ingress by diffusion and drift of material of at least one of the first or second electrodes into the insulator layer.

13. The method of claim 8, wherein the altering occurs after measuring the capacitive value of the MIM capacitor.

14. A method comprising:

forming a metal-insulator-metal (MIM) capacitor including a first electrode and a second electrode and an insulator layer between the first and second electrodes, the MIM capacitor also including a reactive layer,

wherein the reactive layer includes a portion of the first or the second electrode that is in contact with the insulator layer; and

altering the reactive layer to change a capacitive value of the MIM capacitor.

15. The method of claim 14, wherein the altering includes performing a thermal oxidization to convert the reactive layer to a dielectric.

16. The method of claim 15, wherein the altering occurs at approximately 400°

C.

17. The method of claim 14, wherein the altering includes exposing a portion of the reactive layer to a laser in an oxidizing ambient to convert the portion of the conductor material in contact with the insulating layer to a dielectric to reduce an area of the MIM capacitor.

18. The method of claim 17, wherein the reactive layer is selected from the group comprising:

aluminum (Al), silicon (Si), titanium (Ti) and tantalum (Ta) and the oxidizing ambient is selected from the group consisting of;

oxygen (O₂), ozone (O₃), nitrogen oxide (N₂O), carbon dioxide (CO₂) and carbon monoxide (CO).

19. The method of claim 17, wherein the oxidizing ambient temperature is approximately 400°

C.

20. The method of claim 14, wherein the altering occurs after measuring the capacitive value of the MIM capacitor.